Abstract
BACKGROUND: Research on Ultra-Processed Foods (UPF) chiefly focuses on their direct health impacts, with less attention to their wider harms and benefits. This review aimed to synthesise existing evidence on the potential wider impacts of UPF and the mechanisms through which these might operate and to identify evidence gaps to inform research, policy and practice. METHODS: Comprehensive searches on PubMed, Scopus, and Web of Science were done in May 2025. All publication years and languages were considered. Eligible reviews were those that applied a systematic or structured review process. Findings were categorised by domain, level (mechanism, proximal outcome, distal impact), and type of exposure. A narrative synthesis was used to summarise patterns and identify evidence gaps. RESULTS: Of the 386 identified reviews, only six were eligible. Three broad thematic impact areas were identified: commercial, environmental, and social. Commercial mechanisms included foreign direct investment, glocalization, industry-led research, marketing, corporate playbook, and policy influence. These led to proximal impacts: improved productive capacity, increase in UPF sales, market capitalization and consolidation, income redistribution, reduced government revenue, and shifts in policymaking, ultimately reinforcing corporate power. Environmental mechanisms were relatively limited, covering energy, land, water, and pesticide/herbicide use, with proximal impacts including packaging waste, land degradation, rising greenhouse emissions, biodiversity loss, and food loss and waste. Social mechanisms and impacts were less frequently reported and mainly proximal, such as changes to culinary practices, disruption of food culture, and greater food access. None of the reviews discussed fast-food or the wider out-of-home sector. Distal impacts for all three thematic areas were rarely reported; and no review assessed effects on food system resilience. CONCLUSIONS: This review of reviews found that the production, distribution and sale of UPF potentially exert wide-ranging impacts on food systems that go beyond health. However, current reviews provide limited evidence on the environmental and social impacts of UPF. Whilst policies which reduce UPF distribution and consumption are likely to have net population benefits, further research may be needed to understand the interactions between such policies and the multi-faceted impacts of UPF. Consolidation of developing evidence in primary studies, particularly on environmental and social domains, will be essential to fill these gaps and better support robust policymaking.